Container connecting metal fixture

ABSTRACT

A container coupling metal joint of the invention comprises a joint main body  2  having an upper fitting portion  22  and a lower fitting portion  23  capable of respectively fitting into engaging apertures of container corner fittings of the container, a shaft  3  pivoted ratatably to the joint main body  2 , an upper metal fitting  4  and a lower metal fitting  5  capable of respectively engaging with the engaging apertures of the corner fittings of the container, and an operation member  7  for rotating the shaft. The joint main body  2  is provided with a rotation mechanism  6  for rotating the shaft  3  by receiving the action of the load of the container. The shaft  3  is provided with spring means  34  for urging and rotating the upper metal fitting  4  to the position at which it overlaps the upper fitting portion  22 . The upper metal fitting  4  includes cutouts  4   x  formed at diagonally opposite corner portions of the lower face on the side in engagement with the engaging apertures of the corner fittings of the container.

TECHNICAL FIELD

The present invention relates to a container coupling metal joint forcoupling two containers together, disposed between vertically adjacentcontainers stacked in multi-layers in a container yard or on a containership.

BACKGROUND ART

Generally, as shown in FIG. 22, containers Ct are loaded and unloadedfrom a container yard Yd to a container ship Sh and vice versa.

When, for example, containers Ct in the container yard Yd are loadedonto the container ship Sh, the containers Ct are transferred from thecontainer yard Yd onto a container conveying vehicle V such as atrailer, using a transfer crane Tc or a straddle carrier and, then, thecontainers Ct are conveyed to an apron Ap. Next, on the apron Ap, thecontainers Ct are lifted up by a spreader Sp of a container crane Cr andare placed on other containers Ct on the deck of the container ship Sh.

On the other hand, when containers Ct on the deck of the container shipSh are unloaded, the containers Ct are lifted up using the spreader Spof the container crane Cr and are moved to the apron Ap. Then, thecontainers are transferred to the container conveying vehicle V and areconveyed from the apron Ap to the container yard Yd.

In this way, when the containers Ct are stacked in layers in thecontainer yard Yd and on the container ship Sh, in order to prevent thecontainers Ct from coming unfastened and shifted, container couplingmetal joints are disposed respectively between each of the cornerfittings provided on the lower four (4) corners of each container Ct ofan upper layer and each of the corner fittings provided on the upperfour (4) corners of each container Ct of a lower layer and are coupledto each other between counterparts.

Such a container coupling metal joint is described in, for example,International Publication WO92/05093.

First, this container coupling metal joint generally designated at 100will be described with reference to FIGS. 23 to 26.

The container coupling metal joint 100 comprises a joint main body 101dividable to right and left which are fastened together by a bolt as onepart, a shaft 102 (see FIG. 26) pivoted rotatably to the joint main body101 and, an upper cone 103 and a lower cone 104 connected integrally tothe upper end and the lower end, respectively, of the shaft 102.

The joint main body 101 is provided with un upper fitting portion 101Uand a lower fitting portion 101D formed integrally at the top and thebottom thereof, respectively, and each having a shape that coincideswith an engaging aperture Fa (see FIG. 29) of a corner fitting F of acontainer Ct. The upper fitting portion 101U and the lower fittingportion 101D can fit respectively in the engaging aperture Fa of thelower corner fitting F of an upper container Ct and the engagingaperture Fa of the upper corner fitting F of a lower container Ct.

The joint main body 101 includes a through hole (not shown) that extendsthrough the upper fitting portion 101U and the lower fitting portion101D to pivotally receive the shaft 102.

The corner fitting F of the container Ct will not be illustrated indetail herein, but it is defined in JIS Z1616 as well as the engagingaperture Fa.

On the other hand, the upper cone 103 and the lower cone 104 are capableof engaging with the engaging apertures Fa of the corner fittings F ofthe container Ct and are each formed into a shape corresponding to theengaging apertures Fa of the corner fittings F. Furthermore, the uppercone 103 and the lower cone 104 rotate respectively on the upper face ofthe upper fitting portion 101U and on the lower face of the lowerfitting portion 101D of the joint main body 101 as the shaft 102rotates. These upper cone 103 and lower cone 104 are connectedintegrally to the shaft 102, crossing in X when viewed from above suchthat the lower cone 104 comes into engagement with the engaging apertureFa of the upper corner fitting F of the lower container Ct when theupper cone 103 can be freely inserted in and released from the engagingaperture Fa of the lower corner fitting F of the upper container Ct, andthat the upper cone 103 comes into engagement with the engaging apertureFa of the lower corner fitting F of the upper container Ct when thelower cone 104 can freely be inserted in and removed from the engagingaperture Fa of the upper corner fitting F of the lower container Ct.

The lower cone 104 is formed in such a shape that, while the lower cone104 is placed at a position where it engages with the engaging apertureFa of one corner fitting F, a rotation force is applied thereto at themoment when it is pressed into the engaging aperture Fa of the cornerfitting F. That is, the lower cone 104 is shaped such that, under thesituation where the shaft 102 is at a first rotational position Adescribed later with the lower cone 104 being in engagement with theengaging aperture Fa of the corner fitting F, when the lower cone 104 isbrought into contact with and pressed against the edge of the engagingaperture Fa of the corner fitting F, the pressing force is applied tothe corner fitting F through the lower cone 104 whilst the lower cone104 receives a reaction force thereof, with the result that the lowercone 104 is rotated around the rotation axis of the shaft 102 by thereaction force acting on the lower cone 104.

On the other hand, as shown in FIG. 26, within the interior of the jointmain body 101 is formed a cavity 101X having a first locking portion 101a and a second locking portion 101 b against which an arm 1021 securedintegrally to the shaft 102 can be abutted. For this reason, the shaft102 can rotate from the first rotational position A at which the arm1021 abuts against the first locking portion 101 a of the cavity 101X,to a third rotational position C at which the arm 1021 abuts against thesecond locking portion 101 b.

The shaft 102 is disposed with a torsion spring 105 which ordinarilyurges the shaft 102 so that the arm 1021 abuts against the first lockingportion 101 a of the cavity 101 x. Furthermore, a wire 106 is woundaround the shaft 102 along a groove 1022 formed around the shaft 102,with a loop portion at one end of the wire 106 being inserted throughthe arm 1021, the other end being led outside a mouthpiece 107 throughthe mouthpiece 107 disposed slidably on the joint main body 101 andbeing anchored to an operation knob 108. A locking member 1061 is formedin the vicinity of the other end of the wire 106. The locking member1061 can selectively lock into slots 107 a and 107 c formed in the upperpart and the lower part of the mouthpiece 107 that is fitted slidablyvia its right and left ends into a guide 101Y of the joint main body101.

Via its right and left ends the mouthpiece 107 is fitted in the guide101Y of the joint main body 101 and is disposed slidably along the guide101Y such that it is urged ordinarily so as to come into abutmentagainst one end of the guide 101Y by a spring 109 disposed on the jointmain body 101.

In order to couple the upper and lower containers Ct with the containercoupling metal joint 100 having such a structure, first, the containersCt are transferred from the container yard Yd onto the containerconveying vehicle V using the transfer crane Tc and are conveyed to theapron Ap. Then, on the apron Ap, the containers Ct are lifted up to alevel of about one (1) meter above the ground by the spreader Sp of thecontainer crane Cr and are stopped thereat. Then, the upper cone 103 ofthe container coupling metal joint 100 is attached to the lower cornerfittings F of the containers Ct (see FIG. 27). More specifically, theoperation knob 108 is grasped and drawn to lock the locking member 1061of the wire 106 into the slot 107 a of the mouthpiece 107. Under thisstatus, the shaft 102 is at the third rotational position C at which thearm 1021 abuts against the second locking portion 101 b of the cavity101X of the joint main body 101, with the upper cone 103 beingpositioned such that it overlaps the upper fitting portion 101U of thejoint main body 101 when viewed from above. This allows the upper cone103, together with the upper fitting portion 101U of the joint main body101, to be inserted into the engaging aperture Fa of the lower cornerfitting F of the upper container Ct.

After inserting the upper cone 103 into the engaging aperture Fa, theoperation knob 108 is again grasped and drawn to release the lockingmember 1061 of the wire 106 from the slot 107 a of the mouthpiece 107.As a result, the shaft 102 returns by a biasing force of the torsionspring 105 to the first rotational position A at which the arm 1021 ofthe shaft 102 abuts against the first locking portion 101 a of thecavity 101 x of the joint main body 101. Under this status, since theupper cone 103 and the lower cone 104 of the container coupling metaljoint 100 are engaged respectively with the engaging apertures Fa of thecorner fittings F as described above, the container coupling metal joint100 can not fall off the corner fittings F of the container Ct (see FIG.28).

After attaching the container coupling metal joints 100 to the lowercorner fittings F of the container Ct, the container Ct is lifted up bythe container crane Cr and placed on another container Ct on the deck ofthe container ship Sh (see FIG. 29). In this case, the lower cone 104 ofthe container coupling metal joint 100 is rotated forcibly along the rimof the engaging aperture Fa of the upper corner fitting F of thecontainer Ct, against the biasing force of the torsion spring 105 and,when the lower cone 104 overlaps the lower fitting portion 101D of thejoint main body 101 when viewed from above, the lower cone 104 as wellas the lower fitting portion 101D of the joint main body 101 are fittedinto the engaging aperture Fa of the upper corner fitting F of thecontainer Ct. Then, once the lower cone 104 fits into the upper cornerfitting F, the lower cone 104 returns again to the engagement positionby virtue of the biasing force of the torsion spring 105 and is broughtinto engagement with the engaging aperture Fa of the corner fitting F.Consequently, the upper and the lower containers Ct are coupled togetherby the upper cones 103 and the lower cones 104 of the container couplingmetal joint 100 engaged respectively with the lower corner fittings F ofthe upper container Ct and with the upper corner fittings F of the lowercontainer Ct (see FIG. 30).

On the other hand, when the containers Ct on the deck of the containership Sh are unloaded, the lower cone 104 at its engagement position ispulled down or pressed down using the operation knob, causing thelocking member 1061 of the wire 1061 to lock into the slot 107 c of themouthpiece 107. Under this status, the shaft 102 can be disengaged fromthe engaging aperture Fa of the upper corner fitting F of the lowercontainer Ct since the arm 1021 is at a second rotational position Bbetween the first locking portion 101 a and the second locking portion101 b of the cavity 101×of the joint main body 101 so that the lowercone 104 overlaps the lower fitting portion 101D of the joint main body101 when viewed from above (see FIG. 31).

Next, after the containers Ct are lifted up and moved by the spreader Spof the container crane Cr and stopped at a level of about one (1) meterabove the ground, the upper cones 103 of the container coupling metaljoints 100 are released from the lower corner fittings F of thecontainers Ct. That is, by grasping and drawing the operation knob 108,the locking member 1061 of the wire 106 is locked into the slot 107 a ofthe mouthpiece 107. Under this status, as described above, the shaft 102is at the third rotational position C at which the arm 1021 abutsagainst the second locking portion 101 b of the cavity 101X of the jointmain body 101 so that the upper cone 103 overlaps the upper fittingportion 11U of the joint main body 101 when viewed from above. For thisreason, it is possible to disengage the container coupling metal joint100 from the engaging aperture Fa of the lower corner fitting F of theupper container Ct (see FIG. 32). After this, the containers Ct aretransferred from the container crane Cr onto the container conveyingvehicle V by which the containers Ct are conveyed from the apron Ap tothe container yard Yd.

DISCLOSURE OF THE INVENTION

In case of the conventional container coupling metal joint describedhereinabove, when the container is loaded, the container coupling metaljoint is attached to the lower corner fitting of the container to beloaded and, once it is placed on another container, the lower conethereof rotates along the rim of the engaging aperture of the uppercorner fitting of the lower container and it is fitted in the cornerfitting, as a result of which the lower cone is automatically returnedto the position at which it engages with the corner fitting by thetorsion spring so as to allow the upper and lower containers to becoupled together. However, when containers are unloaded, it is necessaryto operate the operation knob to cause the shaft, i.e. the lower cone torotate from the position at which it is engaged with the corner fittingagainst the biasing force of the torsion spring to the position at whichit can be freely inserted or released. That is, as shown in FIG. 31, itis necessary for a worker to pull down or press down the operation knobfrom the uppermost container of containers stacked in multi-layers orfrom the deck (in case of a container ship) or on the ground (in case ofa container yard) using an elongated tool, causing the locking member ofthe wire to be locked into the slot of the mouthpiece. In this case,there are problems that it is difficult to operate securely theoperation knob with the tip of the elongated tool, that much time isnecessary to carry out this work and that the fatigue caused byoperating the heavy elongated tool is considerable. Furthermore, in thecase where the operation starts from the uppermost container, this workhas a disadvantage from the viewpoint of safety since the work iscarried out at an elevated place and it accompanies danger such asfalling down.

The inventors applied before a container coupling metal joint describedin Re-Publication Patent Application WO00/23358 but this joint has adisadvantage that its costs are high and its operation becomes uncertainwhen it is used over a long period of time due to its complicatedstructure.

The present invention was conceived in view of the above problems andthe object thereof is to provide a container coupling metal joint with asimplified structure, capable of coupling automatically the container tobe loaded with the underlying container as well as releasingautomatically the coupled containers without any work at an elevatedplace.

In order to attain the above object, a container coupling metal joint ofthe present invention comprises a joint main body having an upperfitting portion and a lower fitting portion capable of fitting intoengaging apertures of corner fittings of containers; a shaft pivotedrotatably to the joint main body; an upper metal fitting and a lowermetal fitting connected integrally respectively to the upper end and thelower end of the shaft and capable of engaging with the engagingapertures of the corner fittings of the containers; and an operationmember for rotating the shaft, the joint main body being provided with arotation mechanism for rotating the shaft by receiving the action ofload of the container, the shaft being provided with a spring means forurging the upper metal fitting such that the upper metal fitting rotatesto the position at which it overlaps the upper fitting portion, theupper metal fitting having cutouts diagonally oppositely formed atcorner portions of its lower face on the side in engagement with theengaging apertures of the corner fittings of the containers, whereinwhen, through the operation member, the upper metal fitting is at theposition at which it comes into engagement with the engaging aperture ofthe corner fitting of the container, against the biasing force of thespring means, the lower metal fitting is at the position at which itoverlaps the lower fitting portion, wherein when the corner fitting ofthe container presses the rotation mechanism, the shaft is rotatedagainst the biasing force of the spring means, causing the lower metalfitting to rotate to the position at which it comes into engagement withthe engaging aperture of the corner fitting of the container, andwherein when the corner fitting of the container is raised along thecutout of the upper metal fitting and is released from the rotationmechanism, the shaft is rotated by the biasing force of the springmeans, causing the lower metal fitting to rotate to the position atwhich it overlaps the lower fitting portion.

According to this constitution, when the container is loaded, first, theupper metal fitting is rotated to the position at which it overlaps theupper fitting portion and the upper metal fitting is inserted in thelower corner fitting through the engaging aperture of the lower cornerfitting of the container. Inserting of the upper metal fitting into theengaging aperture of the lower corner fitting allows the operationmember to be drawn against the biasing force of the spring means,causing rotation of the upper metal fitting to the position at which itis engaged with the engaging aperture of the lower corner fitting of thecontainer. At this moment, the paired cutouts located at diagonallyopposite positions of the upper metal fitting strike against the lowercorner fitting so that the container coupling metal joint is attached tothe lower corner fitting. The lower corner fitting lies at the positionat which it overlaps the lower fitting portion. Under this status, oncethe lifted container is placed on the underlying container, the lowermetal fitting can be inserted into the upper corner fitting through theengaging aperture of the upper corner fitting of the container.

In this case, since descending of the lifted container leads to abutmentof the lower corner fitting of the container against the rotationmechanism to allow the mechanism to bear the weight, the shaft isrotated against the biasing force of the spring means. For this reason,it is possible to rotate the lower metal fitting from the position atwhich it overlaps the lower fitting portion to the position at which itis engaged with the engaging aperture of the upper corner fitting aswell as to rotate the upper metal fitting to the position at which it isfurther engaged with the engaging aperture of the lower corner fitting,thus enabling the upper container and the lower container to be coupledtogether.

On the other hand, when the container is unloaded, lifting up of thecontainer results, first, in the container ascending by the heightcorresponding to that of the cutouts formed in the upper metal fitting.In consequence, the lower corner fitting of the container is detachedfrom the rotation mechanism so that the shaft is rotated with thebiasing force of the spring means. That is, the lower metal fitting canbe detached from the upper corner fitting through the engaging apertureof the upper corner fitting of the container since the lower metalfitting is rotated from the position at which it is engaged with theengaging aperture of the lower corner fitting to the position at whichit overlaps the lower fitting portion.

In this way, by causing the upper metal fitting to engage with theengaging aperture of the lower corner fitting of the container,transferring the container with the container coupling metal jointattached thereto and placing it on the underlying container, the lowermetal fitting is inserted through the engaging aperture of the uppercorner fitting of the underlying container and, then, the lower metalfitting comes into engagement with the engaging aperture. On thecontrary, since the engaged status of the lower engaging with theengaging aperture of the upper corner fitting of the lower container canbe released when the container is lifted up, it is possible to coupleautomatically the upper and the lower containers by the containercoupling metal joint when the containers are loaded. It is also possibleto release automatically the container coupling metal joint from thelower container when the containers are unloaded. Consequently, theamount of work can be reduced since workers do not need to operate thetools from, e.g., positions on containers and safety can be securedsince the work at an elevated place is unnecessary.

In the above constitution, the rotation mechanism may be a pressingpiece in the shape of substantially a right triangle fitted in slidablyalong a guide aperture and a guide groove formed on the joint main body,and the shaft may be rotated by sliding of the pressing piece pressed bythe corner fitting of the container.

According to this constitution, when the container is lowered, once thelower corner fitting of the container abuts against the slope of thepressing piece and causes the load of the container to act thereon, thepressing piece slides along the guide aperture and the guide groove, andabuts against and thrusts out the shaft. For this reason, the shaft isrotated against the biasing force of the spring means, and the uppermetal fitting and the lower metal fitting are respectively rotated tothe positions at which they are respectively engaged with the engagingapertures of the corner fittings of the containers.

The rotation mechanism may include an ascending/descending membercapable of freely ascending and descending and an articulated linkmechanism abutted by the ascending/descending member and urged always insuch a direction that it is articulated, and the shaft may be rotated bystretching of the articulated link mechanism through theascending/descending member pressed by the corner fitting of thecontainer.

According to this constitution, when the container is lowered, once thelower corner fitting of the container abuts against theascending/descending member and causes the load of the container to actthereon, the articulated link mechanism is stretched through theascending/descending member that is descending, abuts against the shaftand thrusts out the shaft. For this reason, the shaft is rotated againstthe biasing force of the spring means, and the upper metal fitting andthe lower metal fitting are respectively rotated to the positions atwhich they are respectively engaged with the engaging apertures of thecorner fittings of the containers.

The rotation mechanism may be a sliding member slidable along a guidepath formed on the joint main body, and the shaft may be rotated bysliding along the guide path of the sliding member pressed by the cornerfitting of the container.

According to this constitution, when the container is lowered, once thelower corner fitting of the container abuts against the sliding memberand causes the load of the container to act thereon, the sliding memberslides along the guide path, and abuts against and thrusts out theshaft. For this reason, the shaft is rotated against the biasing forceof the spring means, and the upper metal fitting and the lower metalfitting are respectively rotated to the positions at which they arerespectively engaged with the engaging apertures of the corner fittingsof the containers.

The rotation mechanism may include an ascending/descending membercapable of freely ascending and descending along the outer peripheralsurface of the shaft and having an inwardly protruding pin, a spiralgroove formed on the shaft and into which is fitted the pin of theascending/descending member, and a spring urging theascending/descending member to its raised position, and the shaft may berotated by descending of the ascending/descending member pressed by thecorner fitting of the container.

According to this constitution, when the container is lowered, once thelower corner fitting of the container abuts against theascending/descending member and causes the load of the container to actthereon, the ascending/descending member provided with a pin is lowered.At this moment, the pin thrusts downward the spiral groove since the pinis fitted in the spiral groove formed on the shaft. For this reason, theshaft is rotated against the biasing force of the spring means, and theupper metal fitting and the lower metal fitting are respectively rotatedto the positions at which they are respectively engaged with theengaging apertures of the corner fittings of the containers.

The rotation mechanism may include an ascending/descending membercapable of freely ascending and descending along the outer peripheralsurface of the shaft and having a spiral groove formed on its innerperipheral surface, a pin disposed on the shaft and fitted into thespiral groove of the ascending/descending member, and a spring urgingthe ascending/descending member to its upper position, and the shaft maybe rotated by descending of the ascending/descending member pressed bythe corner fitting of the container.

According to this constitution, when the container is lowered, once thelower corner fitting of the container abuts against theascending/descending member and causes the load of the container to actthereon, the ascending/descending member formed with a spiral groovedescends. At this moment, the pin moves along the descending spiralgroove since the pin provided on the shaft is fitted in the spiralgroove. For this reason, the shaft is rotated against the biasing forceof the spring means, and the upper metal fitting and the lower metalfitting are respectively rotated to the positions at which they arerespectively engaged with the engaging apertures of the corner fittingsof the containers.

In the above constitution, it is preferred that the operation memberinclude an operation lever and a connector with its one end connected tothe operation lever and with the other end connected to the shaft, andthat the joint main body be formed with a locking portion capable oflocking the operation lever and a housing portion capable of housing theoperation lever.

According to this constitution, by grasping the operation lever as wellas drawing it against the biasing force of the spring means to allowlocking into the locking portion of the joint main body, it is possibleto rotate the shaft by means of the coupling tool, to rotate the uppermetal fitting and the lower metal fitting secured to the shaftrespectively to the positions at which they are respectively engagedwith the engaging apertures of the corner fittings of the containers andto keep them at those positions.

In the above constitution, the upper fitting portion of the joint mainbody is preferably provided at its one corner portion a stopper urged insuch a direction that it protrudes from the upper face thereof andcapable of freely protruding and retreating, the upper metal fittingbeing abutted against the stopper so that the upper metal fitting isheld at a position at which it is engaged with the engaging aperture ofthe corner fitting of the container.

According to this constitution, the stopper is usually kept protrudedfrom the upper face of the upper fitting portion by the biasing force ofthe spring and the upper metal fitting abuts against the stopper and isat the position at which the upper metal fitting is engaged with theengaging aperture of the corner fitting of the container. For thisreason, by retreating the stopper inside the joint main body, the uppermetal fitting is rotated by the biasing force of the spring means to theposition at which it overlaps the upper fitting portion and the uppermetal fitting can be inserted into the lower corner fitting through theengaging aperture of the lower corner fitting of the container. Underthis status, once the upper metal fitting is rotated to the position atwhich it is engaged with the engaging aperture of the lower cornerfitting by drawing the operation member against the biasing force of thespring means, the stopper is protruded from the upper face of the upperfitting portion by the biasing force of the spring and, thereafter, theupper metal fitting abuts against the stopper, is prevented fromrotating to the position at which it overlaps the upper fitting portionand stays at the position at which it engages with the engaging apertureof the lower corner fitting of the container. For this reason, when thecontainer is transferred with the container coupling metal jointsattached to the lower corner fittings of the container, the containercoupling metal joints can be prevented surely from falling off from thelower corner fittings.

In the above constitution, the joint main body is preferably providedwith a safety mechanism for preventing the rotation of the shaft by thebiasing force of the spring means when the container coupling metaljoint is tilted by a predetermined angle relative to the horizontalplane.

According to this constitution, since the corner fitting of thecontainer is released from the rotation mechanism when the containertilts or jumps by a shake under the status where the upper and the lowercontainers are coupled with each other, the shaft, i.e., the lower metalfitting is attempted to be rotated to the position at which it overlapsthe lower fitting portion. However, the shaft does not rotate since therotation thereof is prevented by the safety mechanism. For this reason,the coupling status of the upper and the lower containers can bemaintained securely.

In the above constitution, arrangement may be such that the safetymechanism includes a receptacle main body formed in the joint main body,a lid body covering the upper opening of the receptacle main body, amoving element provided capable of freely moving back and forth withrespect to the receptacle main body, the moving element being penetratedby the connector and abutted by the operation lever, and a rollingelement capable of freely rolling and arranged on an outward declinedslope formed on the receptacle main body, and that when the safetymechanism is tilted by an angle exceeding a predetermined angle,movement of the moving element is prevented by the rolling element.

According to this constitution, when the upper and lower containers tiltunder the status where they are coupled with each other, the joint mainbody, i.e., the safety mechanism provided on the joint main body is alsotilted, the rolling elements roll along one of the tilted facescorresponding to the direction of the tilt and the backward move of therolling elements is prevented. In this case, the operation lever doesnot move backward as far as the rolling elements do not move since theoperation lever abuts against the rolling elements. Therefore, thecoupler coupled to the operation lever maintains the status as it is andthe rotation of the shaft caused by the biasing force of the springmeans can be securely prevented.

The safety mechanism may include an inclined path declining outwardformed on the joint main body, a rolling element capable of freelyrolling and arranged on the inclined path, and a fitted recess formed onthe shaft, and when the shaft is at the position at which it isrotatable by the articulated mechanism stretched, the inclined path ofthe joint main body and the fitted recess of the shaft may communicatewith each other and, under this status, in the case where the safetymechanism is tilted by an angle exceeding a predetermined angle,rotation of the shaft may be prevented by fitting of the rolling elementinto the fitted recess.

According to this constitution, when the containers tilt under thestatus where they are coupled with each other, the joint main body,i.e., the safety mechanism provided on the joint main body is alsotilted, the rolling elements roll along one of the tilted pathscorresponding to the direction of the tilt and the rolling elements arefitted in the fitted recesses formed on the shaft facing the rollingelements. For this reason, rotation of the shaft caused by the biasingforce of the spring means can be securely prevented.

The safety mechanism may include an inclined path climbing outwardformed on the shaft, a rolling element capable of freely rollingarranged on the inclined path, and a fitted recess formed on the jointmain body, and when the shaft is at the position at which it isrotatable by the sliding member slid, the inclined path of the shaft andthe fitted recess of the joint main body may communicate with each otherand, under this status, in the case where the safety mechanism is tiltedjoint by an angle exceeding a predetermined angle, rotation of the shaftmay be prevented by fitting of the rolling element into the fittedrecess.

According to this constitution, when the containers tilt under thestatus where they are coupled with each other, the joint main body,i.e., the safety mechanism provided on the joint main body is alsotilted, the rolling elements roll along one of the tilted pathscorresponding to the direction of the tilt and the rolling elements arefitted in the fitted recesses formed on the joint main body facing therolling elements. For this reason, rotation of the shaft caused by thebiasing force of the spring means can be securely prevented.

The safety mechanism may include an inclined path declining outwardformed on the joint main body, a rolling element capable of rolling andarranged on the inclined path, and a fitted recess formed on theascending/descending member, and when the ascending/descending member isat its lowered position, the inclined path of the joint main body andthe fitted recess of the ascending/descending member may communicatewith each other and, under this status, in the case where the safetymechanism is tilted by an angle exceeding a predetermined angle,ascending of the ascending/descending member may be prevented by fittingof the rolling element into the fitted recess.

According to this constitution, when the containers tilt under thestatus where they are coupled with each other, the joint main body,i.e., the safety mechanism provided on the joint main body is alsotilted, the rolling elements roll along one of the tilted pathscorresponding to the direction of the tilt and the rolling elements arefitted in the fitted recesses formed on the ascending/descending memberfacing the rolling elements. For this reason, ascending of theascending/descending member is prevented. In this case, the shaft doesnot rotate as far as the ascending/descending member does not ascendsince the pin is fitted in the spiral groove. Therefore, the rotation ofthe shaft caused by the biasing force of the spring means can besecurely prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an entire perspective view of a first embodiment of acontainer coupling metal joint of the present invention;

FIG. 2 is an exploded perspective view of the container coupling metaljoint shown in FIG. 1;

FIG. 3 is a perspective view showing a half of a joint metal bodyconstituting the container coupling metal joint shown in FIG. 1;

FIG. 4 is a perspective view showing a shaft, and an upper metal fittingand a lower metal fitting attached integrally to the shaft, constitutingthe container coupling metal joint shown in FIG. 1;

FIG. 5 is a perspective view showing the backside of the upper metalfitting;

FIG. 6 is a cross-sectional view on a plane crossing an upper fittingportion of the joint main body of the container coupling metal jointshown in FIG. 1;

FIG. 7 is a perspective view illustrating a safety mechanismconstituting the container coupling metal joint shown in FIG. 1 and theaction thereof;

FIG. 8 is a front view illustrating a status where the containercoupling metal joint coupling the upper and the lower containers istilted at a specific angle relative to a horizontal plane and across-sectional view taken along line A-A;

FIG. 9 is a perspective view showing the backside of an example ofvariation of the upper metal fitting;

FIG. 10 is a perspective view illustrating the process of attaching thecontainer coupling metal joint shown in FIG. 1 to a lower corner fittingof a container;

FIG. 11 is a partially-exploded perspective view illustrating the statuswhere the container coupling metal joint shown in FIG. 1 is attached tothe lower corner fitting of the container;

FIG. 12 is a perspective view illustrating the process of attaching thecontainer coupling metal joint shown in FIG. 1 attached to the lowercorner fitting of the container, to un upper corner fitting of anothercontainer;

FIG. 13 is a partially-exploded perspective view illustrating the statuswhere the upper metal fitting and the lower metal fitting of thecontainer coupling metal joint shown in FIG. 1 are respectively engagedwith the lower corner fitting and the upper corner fitting of respectivecontainers and the upper and the lower containers are coupled;

FIG. 14 is a perspective view illustrating the process of unloading theupper container coupled to the lower container with the containercoupling metal joint shown in FIG. 1, from the lower container;

FIG. 15 is a partially-omitted longitudinal cross-sectional viewillustrating a second embodiment of the container coupling metal jointof the invention;

FIG. 16 is a transverse cross-sectional view of the container couplingmetal joint shown in FIG. 15;

FIG. 17 illustrates is a partially-omitted longitudinal cross-sectionalview illustrating a third embodiment of the container coupling metaljoint of the invention;

FIG. 18 is a transverse cross-sectional view of the container couplingmetal joint shown in FIG. 17;

FIG. 19 is a transverse cross-sectional view showing the status wherethe upper metal fitting and the lower metal fitting of the containercoupling metal joint shown in FIG. 17 are respectively at the positionat which each of them respectively engages at the corner fitting of thecontainer;

FIG. 20 is a partially-omitted longitudinal cross-sectional viewillustrating a fourth embodiment of the container coupling metal jointof the invention;

FIG. 21 is a transverse cross-sectional view of the container couplingmetal joint shown in FIG. 20;

FIG. 22 is a view illustrating a situation where containers aretransferred between a container yard and an apron by a containerconveying vehicle and containers are loaded or unloaded between thecontainer conveying vehicle and a container ship by a container crane;

FIG. 23 is a perspective view of a conventional container coupling metaljoint;

FIG. 24 is a plan view of the container coupling metal joint shown inFIG. 23;

FIG. 25 is a bottom plan view of the container coupling metal jointshown in FIG. 23;

FIG. 26 is a transverse cross-sectional view of the container couplingmetal joint shown in FIG. 23;

FIG. 27 is a view illustrating the process of the work of attaching thecontainer coupling metal joint shown in FIG. 23 to a container andloading the container on the container ship;

FIG. 28 is a view illustrating the process of the work of attaching thecontainer coupling metal joint shown in FIG. 23 to a container andloading the container on the container ship;

FIG. 29 is a view illustrating the process of the work of attaching thecontainer coupling metal joint shown in FIG. 23 to a container andloading the container on the container ship;

FIG. 30 is a view illustrating the process of the work of attaching thecontainer coupling metal joint shown in FIG. 23 to a container andloading the container on the container ship;

FIG. 31 is a view illustrating the process of the work of unloading fromthe container ship containers loaded being coupled to each other by thecontainer coupling metal joint shown in FIG. 23; and

FIG. 32 is a view illustrating the process of the work of unloading fromthe container ship containers loaded being coupled to each other by thecontainer coupling metal joint shown in FIG. 23.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the invention will be described hereinbelow withreference to the drawings.

FIGS. 1 and 2 show a first embodiment of a container coupling metaljoint 1 of the invention.

This container coupling metal joint 1 comprises a joint main body 2dividable to right and left and fastened together by a bolt as one part,a shaft 3 pivoted rotatably to the joint main body 2, an upper metalfitting 4 connected to the upper end of the shaft 3 as one part, a lowermetal fitting 5 connected to the lower end of the shaft 3, a rotationmechanism 6 for rotating the shaft 3 when the load of the container Ctworks on it, an operating member 7 for rotating the shaft 3, i.e., theupper metal fitting 4 and the lower metal fitting 5 and a safetymechanism 8 for limiting the rotation of the shaft 3.

The joint main body 2 comprises a main body portion 21 which is largerthan the engaging aperture Fa of the corner fitting F of the containerCt, an upper fitting portion 22 and a lower fitting portion 23respectively provided on the upper portion and the lower portion of themain body portion 21 and having a shape engaged with the engagingaperture Fa of the corner fitting F of the container Ct. These upperfitting portion 22 and the lower fitting portion 23 are adapted to beable to be respectively engaged with the engaging aperture Fa of thelower corner fitting F of an upper container Ct and the engagingaperture Fa of the upper corner fitting F of a lower container Ct. Atthe front end of the main body portion 21 of the joint main body 2, alocking portion 21 a for locking an operation lever 71 of an operatingmember 7 is formed and a housing portion 21 b capable of housing theoperation lever 71 is formed.

On the joint main body 2, as shown in FIG. 3, substantially in themiddle thereof in the vertical direction, a cylindrical first cavity 2 ais formed and a cuboidal second cavity 2 b is formed above the firstcavity 2 a sandwiching a barrier between it and the first cavity 2 a. Acylindrical third cavity 2 c having a diameter smaller than that of thefirst cavity 2 a is formed below the first cavity 2 a and communicablywith the first cavity 2 a. Furthermore, in the joint main body 2, athrough hole 2 d is formed with its center aligned on the centers of thefirst cavity 2 a and the third cavity 2 c, that penetrates from theupper face of the upper fitting portion 22 to the lower face of thelower fitting portion 23. In front of the main body portion 21 of thejoint main body 2, a fourth cavity 2 e having an x-letter shape whenviewed from above is formed, of which one end communicates with thefirst cavity 2 a and the other end opens at the front end of the mainbody portion 21 (the locking portion 21 a).

As described later, a flange portion 32, arms 33 of the shaft 3 pivotedrotatably to the through hole 2 d of the joint main body 2, and atorsion spring 34 disposed around the shaft 3 are respectively housed inthe first cavity 2 a, the second cavity 2 b and the third cavity 2 cand, furthermore, the safety mechanism 8 is housed in the fourth cavity2 e.

Furthermore, a stopper 24 is formed on the joint main body 2 at its onecorner, which is capable of being protruded and retreated and is urgedthrough a spring not shown such that it is protruded from the upper faceof the upper fitting portion 22. The stopper 24 includes an operationrod 241 formed integrally therewith such that the stopper 24 can retreatinside the joint main body 2 so as not to protrude from the upper faceof the upper fitting portion 22 by pressing down the operation rod 241against the biasing force of the spring.

A recess 21 c is formed on the main body portion 21 of the joint mainbody 2 such that the operation rod 241 can be pressed down for apredetermined distance.

As shown in FIGS. 2 and 4, the shaft 3 comprises, formed integrallytherewith, a shaft portion 31 having an outer diameter corresponding tothe diameter of the through hole 2 d of the joint main body 2, theflange portion 32 having a diameter larger than that of the shaftportion 31 substantially in the middle of the shaft portion 31 and apair of arms 33 protruding outward at an interval of about 180 degreeson the outer peripheral surface of the shaft portion 31 above the flangeportion 32. The flange portion 32 and the arms 33 are respectivelypositioned such that the flange portion 32 is housed in the first cavity2 a of the joint main body 2 and the arms 33 are housed in the secondcavity 2 b.

Furthermore, below the shaft portion 31 of the shaft 3, sparing means,for example, a torsion spring 34 is fitted and one end of this torsionspring 34 is anchored at the flange portion 32 of the shaft 3 and theother end of it is anchored at the joint main body 2. In FIG. 4, theshaft 3 is urged such that it rotates counterclockwise (in the directionshown by the arrow) by the force of the torsion spring 34.

On the other hand, one end of a connecting tool, for example, a controlcable 72 such as of Kevlar, of operation member 7 is anchored at theflange portion 32 of the shaft 3 and the other end of it is anchored atthe operation lever 71 through the safety mechanism 8.

The upper metal fitting 4 is fixed integrally at the upper end of theflange portion 31 of the shaft 3 and is formed in a shape correspondingto the engaging aperture Fa of the lower corner fitting F of thecontainer Ct when viewed from above. Therefore, when the upper metalfitting 4 is positioned such that it overlaps the upper fitting portion22 of the joint main body 2, the upper metal fitting 4 can be insertedinto the lower corner fitting F through the engaging aperture Fa and,when inserted, the upper fitting portion 22 is engaged with the engagingaperture Fa of the lower corner fitting. Yet furthermore, a cutout 4 xis formed in the upper metal fitting 4 at the lower corner on a diagonalthat intersects the right and left outer faces of the upper fittingportion 22 when the upper metal fitting 4 is positioned intersecting theupper fitting portion 22 at a specific angle, i.e., is positioned suchthat the upper metal fitting 4 can engaged with the engaging aperture Faof the lower corner fitting F of the container Ct. The cutout 4 x of theupper metal fitting 4 has a size being set such that the lower cornerfitting F can be elevated by the height corresponding to the substantialthickness of the cutout 4 x when the upper metal fitting 4 is positionedsuch that it can be engaged with the engaging aperture Fa of the lowercorner fitting F of the container Ct. The outer face of the upper metalfitting 4 is chamfered in a curved plane such that it can smoothlycontact the inner face of the engaging aperture Fa of the lower cornerfitting F.

The lower metal fitting 5 is fixed integrally at the lower end of theshaft portion 31 of the shaft 3 and is formed in a shape correspondingto that of the engaging aperture Fa of the upper corner fitting F of thecontainer Ct when viewed from above. Therefore, when the lower metalfitting 5 is positioned such that the lower metal fitting 5 overlaps thelower fitting portion 23 of the joint main body 2, the lower metalfitting 5 can be inserted into the upper corner fitting F through theengaging aperture Fa and, when inserted, the lower fitting portion 23 isengaged with the engaging aperture Fa of the upper corner fitting F.

In this case, the upper metal fitting 4 and the lower metal fitting 5are fixed to the shaft 3 crossing each other in an x-letter shape whenviewed from above. When the upper metal fitting 4 is caused to abutagainst the stopper 24 by the biasing force of the torsion spring 34 andis positioned such that it can be engaged with the engaging aperture Faof the lower corner fitting F of the container Ct, the lower metalfitting 5 is positioned at a position such that it overlaps the lowerfitting portion 23 of the joint main body 5, i.e., at the position atwhich the lower metal fitting 5 can be inserted into and released fromthe engaging aperture Fa of the upper corner fitting F of the containerCt (see FIG. 1). On the other hand, when the upper metal fitting 4 isrotated clockwise against the biasing force of the torsion spring 34from the position at which it abuts against the stopper 24 to theposition at which it is engaged with the engaging aperture Fa of theupper corner fitting F of the container Ct, the lower metal fitting 5 isalso positioned where it can be engaged with the engaging aperture Fa ofthe upper corner fitting F of the container Ct.

When the upper metal fitting 4 is positioned such that it abuts againstthe stopper 24, as shown by the solid line in FIG. 1, the operationlever 71 is housed in the housing portion 21 b under a status wherethere is some room to the end of the depth of the housing portion 21 b.Therefore, when the upper metal fitting 4 is rotated counterclockwise bythe biasing force of the torsion spring 34 to the position at which itoverlaps the upper fitting portion 22 by causing stopper 24 to retreatinward the joint main body 2 by pressing down the operation rod 241, theoperation lever 71 is drawn through the control cable 72 to the positionat which the operation lever 71 abuts against the end of the depth ofthe housing portion 21 b. On the other hand, when the operation lever 71is grasped and drawn in the direction leaving the paper upward suchthat, as indicated by the dotted line in FIG. 1, it is rotated by 90degrees and caused to intersect the fitting main body 2 and to lock thelocking portion 21 a, the counterclockwise rotation of the shaft 3caused by the biasing force of the torsion spring 34 can be limitedthrough the control cable 72 connected between the shaft 3 and theoperation lever 71. In this case, the shaft 3, i.e., the upper metalfitting 4 and the lower metal fitting 5, rotated counterclockwisethrough the control cable 72 against the biasing force of the torsionspring 34 are positioned at a position where the upper metal fitting 4and the lower metal fitting 5 can respectively be engaged with theengaging apertures Fa of the corner fittings F of respective containersCt.

The rotation mechanism 6 is a pair of pressing pieces 61 in the shape ofsubstantially a right angle isosceles triangle disposed slidably on theupper fitting portion 22 of the joint main body 2. Each pressing piece61 is slidably fitted in each guide aperture 61 a (see FIG. 6) havingsubstantially an ellipsoidal cross-section, formed in communication withthe second cavity 2 b and extending vertically in its longitudinaldirection from the left and right outer sides, at substantially thediagonally opposite positions of the upper fitting portion 22 on theside intersecting in X the upper metal fitting 4 when the upper metalfitting 4 is at a position at which it is engaged with the engagingaperture Fa of the lower corner fitting F. Guide grooves 61 b having asemi-circular cross-section and communicating with the guide apertures61 a are formed on the upper face of the main body portion 21 and on theupper and lower faces of the second cavity 2 b such that, when thepressing pieces 61 slide along the guide aperture 61 a, the base and thetop side of the pressing piece 61 are respectively guided by the guidegroove 61 b.

The pressing pieces 61 are fitted in the guide apertures 61 a such thatthe slopes of the pressing pieces 61 are positioned facing outward. Whenthe lower corner fitting F of the container Ct abuts against the slopeof the pressing piece 61, the pressing piece 61 is thrust into thesecond cavity 2 b along the guide aperture 61 a and the guide groove 61b by the weight of the container Ct.

Then, the tip of the pressing piece 61 is set such that it abuts againsteach arm 33 in the second cavity 2 b and, for example, when the uppermetal fitting 4 is caused to abut the stopper 24 by the biasing force ofthe torsion spring 34, the pressing piece 61 is struck against by thearm 33 of the shaft 3 and thrust out by it along the guide aperture 61 aand the guide groove 61 b as shown in FIG. 6.

The safety mechanism 8 can be fitted in the fourth cavity 2 e of thejoint main body 2 and, as shown in FIG. 7(a), comprises a receptaclemain body 81 formed in an approximate x-letter shape, a lid body 82which is formed in an substantially vertically symmetric shape to thereceptacle main body 81 and opens and closes the upper opening of thereceptacle main body 81 (see FIG. 7(d)), a moving element 83 in anX-letter shape, arranged on the receptacle main body 81 and movableforward and backward, a spring 84 disposed on the receptacle main body81 and the moving element 83 and always thrusting forward the movingelement 83, rolling elements, for example, a pair of balls 85respectively capable of rolling on each of slopes 8 x (see FIG. 8(b))formed on the bottom plane of the receptacle main body 81 and decliningoutward to right and left, guides 86 formed in the receptacle main body81 and forming housing spaces for the balls 85 such that the guides donot interfere with the right and left end faces of the moving element83. Each ball 85 can roll on the slope 8 x in a space extending to rightand left defined by the guide 86 provided on the receptacle main body81, the moving element 83 and the receptacle main body 81.

A locking portion 8 a and a housing portion 8 b that are fitted in thelocking portion 21 a and the housing portion 21 b of the joint main body2 when the safety mechanism 8 is arranged in the fourth cavity 2 e ofthe joint main body 2, are formed on the receptacle main body 81 and thelid body 82.

An inserting through hole (not shown) is formed in the direction fromthe front to the back in the moving element 83. The control cable 72inserted through the inserting through hole of the moving element 83 isanchored to the operation lever 71 striking against the front end of themoving element 83.

When the receptacle main body 81 is placed horizontally, each ball 85contacts the inner wall surface on the right and the left at the lowestend of the slope 8 x. At this moment, once the control cable is drawnbackward, the moving element 83 can move backward against the biasingforce of the spring 84 through the operation lever 71 housed in thehousing portion 8 b, 21 b in a status where there is room to the end ofthe depth of them. At this moment, the operation lever 71 is housed inthe status where the operation lever 71 abuts against the end of thedepth of the housing portion 8 b (see FIG. 7(b)).

On the other hand, when the receptacle main body 81 is tilted by apredetermined angle from the horizontal position, more specifically,when it is tilted by an angle exceeding the inclination of the slope 8 x(being set to approximately five (5) degrees in this embodiment), eitherone ball 85 rolls on the slope 8 x in the space extending to the rightand left and defined by the guide 86, the moving element 83 and thereceptacle main body 81. Since a ball 85 is present between the movingelement 83 and the receptacle main body 81, even if the control cable 72is drawn backward, move of the moving element 83 is prevented.Therefore, the operation lever 71 does not move from the positioncorresponding to the locking portion 8 a (see FIG. 7(c) and FIG. 8(b))and the rotation of the shaft 3 is prevented.

Instead of the cutouts 4 x of the upper metal fitting 4 of theabove-described embodiment, as shown in FIG. 9, cutouts formed by thehorizontal plane positioned at the height substantially corresponding tothe plate thickness of the corner fitting F and a vertical planecontinuing on each of the right and left outer sides of the upperfitting portion 22 is also available.

A case where balls 85 are used as the rolling elements of the safetymechanism 8 has been described. However, the rolling elements may berollers.

Next, the action of the container coupling metal joint 1 will bedescribed.

First, at the initial status, as shown in FIGS. 1 and 2, the upper metalfitting 4 is caused to abut against the stopper 24 by the biasing forceof the torsion spring 34 and is at the position at which it is engagedwith the engaging aperture Fa of the lower corner fitting F of thecontainer Ct. At this moment, the lower metal fitting 5 is at theposition at which it overlaps the lower fitting portion 23 of the jointmain body 2. As shown in FIG. 6, the pressing piece 61 is abutted by thearm 33 of the shaft 3 and is thrust outward along the guide aperture 61a and the guide groove 61 b. Furthermore, the operation lever 71 ishoused in the housing portion 21 b of the joint main body 2 (the housingportion 8 b of the safety mechanism 8) remaining some room to the end ofthe depth of the housing portion 21 b.

In order to attach the container coupling metal joint 1 to the engagingaperture Fa of the corner fitting F of the container Ct, first, thestopper 24 is caused to retreat inside the joint main body 2 from theposition at which the stopper 24 is protruded from the upper face of theupper fitting portion 22 by pressing down the operation rod 241 againstthe biasing force of the spring. At this moment, since the limitation onthe rotation of the upper metal fitting 4 by the stopper 24 is released,the shaft 3 is rotated to the position at which the upper metal fitting4 overlaps the upper fitting portion 22 by the biasing force of thetorsion spring 34. During this, the operation lever 7 is drawn backwardthrough the control cable 72 by the distance created by the rotation ofthe shaft 3, and is housed in the housing portion 21 b of the joint mainbody 2 (the housing portion 8 b of the safety mechanism 8) strikingagainst the end of the depth of the housing portion 21 b (see FIG.7(b)).

Under this status, the upper metal fitting 4 is inserted into the lowercorner fitting F through the engaging aperture Fa of the lower cornerfitting F of the container Ct lifted up at the height of about one (1)meter on the ground by the container crane Ct, by lifting up thecontainer coupling metal joint 1 on the apron Ap (see FIG. 10).Following this, once the operation lever 71 is drawn against the biasingforce of the torsion spring 34, the shaft 3 is rotated clockwise and theupper metal fitting 4 is rotated to the position at which it is engagedwith the engaging aperture Fa inside the lower corner fitting F. Duringthis, the stopper 24 is protruded from the upper face of the upperfitting portion 22 by the biasing force of the spring by the rotation ofthe upper metal fitting 4 to the position at which it is engaged withthe engaging aperture Fa of the corner fitting F and, after this, theupper metal fitting 4 abuts against the stopper 24, is prevented fromrotating counterclockwise by the biasing force of the torsion spring 34any more and is held at the position at which it is engaged with theengaging aperture Fa of the lower corner fitting F. Therefore, even if ahand holding the container coupling metal joint 1 leaves it, thecontainer coupling metal joint 1 is securely prevented from falling downfrom the lower corner fitting F of the container Ct since the uppermetal fitting 4 is engaged with the engaging aperture Fa of the lowercorner fitting F.

At this moment, the lower metal fitting 5 is at the position at which itoverlaps the lower fitting portion 23. The container coupling metaljoint 1 descends due to its own weight and the cutouts 4 x of the uppermetal fitting 4 contact the inner peripheral surface of the engagingaperture Fa of the lower corner fitting F and are held there as well asthe upper fitting portion 22 is partially engaged with the engagingaperture Fa of the lower corner fitting F (see FIG. 11).

When the container coupling metal joint 1 has been attached as a resultof engagement of the upper metal fitting 4 with the engaging aperture Faof the lower corner fitting F of the container Ct, the container Ct islifted up using the container crane Cr and is loaded on the containership Sh. During this, since the upper metal fitting 4 is at the positionat which it is engaged with the engaging aperture Fa of the lower cornerfitting F of the container Ct that is lifted up, being limited by thestopper 24 as described above, the container coupling metal joint 1 cannot fall off from the lower corner fitting F of the container Ct whilethe container Ct is moved from the Apron to the deck of the containership Sh.

On the other hand, since the lower metal fitting 5 is at the position atwhich it overlaps the lower fitting portion 23, the lower metal fitting5 can be inserted into the upper corner fitting F through the engagingaperture Fa of the upper corner fitting F of the lower container Ctloaded earlier. At this moment, the lower fitting portion 23 is engagedwith the engaging aperture Fa of the upper corner fitting F (see FIG.12).

Further descending of the upper container Ct allows the lower face ofthe main body portion 21 of the joint main body 2 to be placed on theupper face of the upper corner fitting F of the lower container Ct,after which the upper container Ct descends by the height correspondingto the height of the cutouts 4 x of the upper metal fitting 4. Since, atthis moment, the lower corner fitting F abuts against the slope of thepressing piece 61 protruding outward from the upper fitting portion 22of the joint main body 2 and bears the weight of the upper container Ct,the pressing piece 61 is thrust in toward the second cavity 2 b of thejoint main body 2 along the guide aperture 61 a and the guide groove 61b. On the other hand, since the pressing piece is thrust in toward thesecond cavity 2 b of the joint main body 2, the arm 33 of the shaft 3against which the tip of the pressing piece 61 abuts is thrust outagainst the biasing force of the torsion spring 34, with the result thatthe shaft 3 is rotated clockwise and, inside the upper corner fitting Fof the lower container Ct, causes the lower metal fitting 5 to rotate tothe position at which it can be engaged with the engaging aperture Fa.Similarly, the upper metal fitting 4 is also rotated to the position atwhich it is further engaged with the engaging aperture Fa of the lowercorner fitting F of the upper container Ct (see FIG. 13). Then, finally,the lower face of the lower corner fitting F of the upper container Ctis placed on the upper face of the main body portion 21 of the jointmain body 2.

Consequently, the upper and the lower containers Ct are coupled throughthe container coupling metal joint 1 of which the upper metal fitting 4and the lower metal fitting 5 are respectively rotated to the respectivepositions at which each of them are respectively engaged with theengaging apertures Fa of the corner fittings F.

The operation lever 71 is thrust out from the housing portion 21 b ofthe joint main body 2 to the position corresponding to the lockingportion 21 a through the control cable 72 connected to the shaft 3.

Under the status where the upper and the lower containers Ct are coupledthrough the container coupling metal joint 1, if the container ship Shrolls and is tilted by an angle exceeding a predetermined angle relativeto the horizontal plane, since, in the safety mechanism 8, one of theballs 85 rolls along the slope 8 x and the moving element 83 and theball 85 interfere with each other, the backward move of the movingelement 83 can be prevented (see FIG. 7(c) and FIG. 8(b)).

That is, even when the lower corner fitting F of the container Ct isreleased from the pressing piece 61 due to the tilting or the jumping ofthe containers Ct caused by the rolling or pitching of the containership Sh, the shaft 3 is attempted to rotate by the biasing force of thetorsion spring 34 such that the lower metal fitting 5 overlaps the lowerfitting portion 23. However, at this moment, since the operation lever71 with the control cable 72 anchored to it abuts against the movingelement 83 being prevented from moving backward by the ball 85, theoperation lever 71 can not move.

Consequently, the shaft 3, i.e., the lower metal fitting 5 is rotated tothe position at which it overlaps the lower fitting portion 23 and thelower metal fitting 5 is released from the engaging aperture Fa of theupper corner fitting F of the lower container Ct. Therefore, the coupledstatus of the upper and the lower containers Ct by the containercoupling metal joint 1 is securely prevented from being released.

For example, when stormy weather is expected during a voyage, it isnecessary to rotate the operation lever 71 at the position correspondingto the locking portion 21 a of the joint main body 2, by 90 degrees tolock with the locking portion 21 a (see the position indicated by thedotted line in FIG. 1 and FIG. 7(d)) and, by doing so, counterclockwiserotation of the shaft 3 caused by the biasing force of the torsionspring 34 can be prevented. However, even though the operation forrotating the operation lever 71 is forgotten, the upper metal fitting 5can be securely prevented from being released from the engaging apertureFa of the upper corner fitting F of the lower container Ct by preventingthe counterclockwise rotation by the torsion spring 34 of the shaft 3 bythe safety mechanism 8.

On the other hand, when the container Ct is unloaded from the containership Sh, it is enough that the container Ct is lifted up through thecontainer crane Cr. That is, when the upper container Ct is lifted up,first, only the upper container Ct is lifted up by the height of thecutouts 4 x of the upper metal fitting 4. During this, the shaft 3 isrotated counterclockwise by the biasing force of the torsion spring 34due to releasing off of the lower corner fitting Fa of the uppercontainer Ct from the slope of the pressing piece 61 and the pressingpiece 61 is thrust out by the arm 33. That is, the shaft is rotatedcounterclockwise by the biasing force of the torsion spring 34 to theposition at which the upper metal fitting 4 abuts against the stopper24. At this moment, the container coupling metal joint 1 can be releasedfrom the upper corner fitting F of the lower container Ct since theupper metal fitting 5 is at the position at which it overlaps the lowerfitting portion 23 (see FIG. 14).

In this way, the lower metal fitting 5 of the container coupling metaljoint 1 can be securely released from the upper corner fitting F of thelower container Ct by only lifting up the upper container Ct. Therefore,the operation of operation tools by workers or work at high places areunnecessary. In this case, as described before, the upper metal fitting4 is at the position at which it is engaged with the engaging apertureFa of the lower corner fitting F of the lifted container Ct. Therefore,the container coupling metal joint 1 can not fall off from the lowercorner fitting F of the container Ct during the transfer of it from thecontainer ship Sh to the apron Ap.

When the container Ct has been transferred to the apron Ap, once theoperation rod 241 is pressed down on the apron Ap, the shaft 3 isrotated counterclockwise by the biasing force of the torsion spring 34since the stopper 24 is retreated inside the joint main body 2, and theupper metal fitting 4 is rotated to the position at which it overlapsthe upper fitting portion 22. Therefore, the upper metal fitting 4together with the upper fitting portion 22, i.e., the container couplingmetal joint 1 can be released from the engaging aperture Fa of the lowercorner fitting F of the container Ct.

In the embodiment described above, a case is described where the uppermetal fitting 4 is held at the position it is engaged with the engagingaperture Fa of the lower corner fitting F of the container Ct byproviding the stopper 24 and causing the upper metal fitting 4 to abutagainst the stopper 24. However, it is possible to adapt that, insteadof the stopper 24 or with the stopper 24, at the front end of the jointmain body 2 and front end of the safety mechanism 8, a second lockingportion intersecting the housing portion 21 b and 8 b at a right angleand having a groove-like shape with a depth slightly shallower than thedepth of the housing portion 21 b and 8 b is formed to lock theoperation lever 71 at the new second locking portion and the upper metalfitting 4 is held at the position at which it is engaged with theengaging aperture Fa of the corner fitting F of the container Ct.

FIGS. 15 and 16 show a second embodiment of the container coupling metaljoint 1 of the invention.

For describing the second embodiment of the container coupling metaljoint 1, the same reference numbers are given to the members same as themembers constituting the first embodiment of the container couplingmetal joint 1 described above. The detailed description for thosemembers is omitted and only the rotation mechanism 6 and the safetymechanism 8 that differ from those of the first embodiment will bedescribed.

The rotation mechanism 6 in this container coupling metal joint 1,comprises an ascending/descending member 62 provided on the main bodyportion 21 of the joint main body 2, being capable of being protrudedand retreated and an articulated link 63, such as a chain, having aplurality of articulated points arranged below the ascending/descendingmember 62 in a housing space formed in the main body portion 21 of thejoint main body 2, communicating with the cavity 2 f. At the eacharticulated point of the articulated link 63, a spring not shown isprovided and the articulated link 63 is urged in the direction it isarticulated. The tip of the articulated link 63 is protruded into thecavity 2 f of the joint main body 2 through the housing space and thetop of the tip abuts against a engaged portion 3 a formed in the shaft3. The ascending/descending member 62 is protruded above the upper faceof the main body portion 21 of the joint main body 2 by the articulatedlink 63 that is articulated.

On the other hand, the safety mechanism 8 comprises a pair of inclinedpaths 2 x that are declining and formed extending in the direction ofthe diameter of the through hole 2 d and, of which one end opens to thecavity 2 f of the joint main body 2, a plurality of balls 85 as rollingelements arranged in such a manner as to be able to roll on eachinclined path 2 x and a pair of fitted recesses 3 x formed in the shaft3 corresponding to each opening of the inclined paths 2 x. When theshaft 3 is rotated by a predetermined angle by the articulated link 63that is stretched, each inclined path 2 x of the joint main body andeach fitted recess 3 x of the shaft 3 are set to respectivelycommunicate with each other.

The inclined paths 2 x are provided being spaced by 180 degrees fromeach other at positions shifted by a predetermined angle such that theydo not interfere with the housing space housing the articulated link 63.

Next, the action of the second embodiment of the container couplingmetal joint 1 structured as described above will be described.

First, in the initial status, the upper metal fitting 4 is at theposition at which it is engaged with the engaging aperture Fa of thelower corner fitting F of the container Ct by being struck against bythe stopper 24. At this moment, the lower metal fitting 5 is at theposition at which it overlaps the lower fitting portion 23 of the jointmain body 2. The ascending/descending member 62 is at its raisedposition by the biasing force of the articulated link 63 that isarticulated, and is protruded above the upper face of the main bodyportion 21 of the joint main body 2.

In order to attach the container coupling metal joint 1 in the engagingaperture Fa of the corner fitting F of the container Ct, first, thestopper 24 is retreated inside the joint main body 2 by pressing downthe operation rod 241. During this, the shaft 3 is rotated by thebiasing force of the torsion spring 34 to the position at which theupper metal fitting 4 overlaps the upper fitting portion 22. Therefore,the operation lever 71 is drawn backward through the control cable 72 bythe distance created by the rotation of the shaft 3, abuts against theend of the depth of the housing portion 21 b of the joint main body 2and is housed there.

Under this status, the container coupling metal joint 1 is lifted andthe upper metal fitting 4 is inserted into the lower corner fitting Fthrough the engaging aperture Fa of the lower corner fitting F of thecontainer Ct that is lifted up. After this, by drawing the operationlever 71 against the biasing force of the torsion spring 34, the shaft 3is rotated clockwise and the upper metal fitting 4 is rotated in thelower corner fitting F to the position at which it can be engaged withthe engaging aperture Fa. During this, the stopper 24 is protruded fromthe upper face of the upper fitting portion 22 by the biasing force ofthe spring. After this, the upper metal fitting 4 abuts against thestopper 24, is prevented from rotating counterclockwise any more and isheld at the position at which it is engaged with the engaging apertureFa of the lower corner fitting F.

In this case, the lower metal fitting 5 is at the position at which itoverlaps the lower fitting portion 23. The container coupling metaljoint 1 descends due to its own weight and the cutouts 4 x of the uppermetal fitting 4 contact the inner peripheral surface of the engagingaperture Fa of the lower corner fitting F and are held there as well asthe upper fitting portion 22 is partially engaged with the engagingaperture Fa of the lower corner fitting F.

When the container coupling metal joint 1 has been attached as a resultof engagement of the upper metal fitting 4 with the engaging aperture Faof the lower corner fitting F of the container Ct, the container Ct islifted up using the container crane Cr and is loaded on the containership Sh. At this moment, since the upper metal fitting 4 is at theposition at which it is engaged with the engaging aperture Fa of thelower corner fitting F of the container Ct that is lifted up, thecontainer coupling metal joint 1 can not fall off from the lower cornerfitting F of the container Ct while the container Ct is moved from theApron to the deck of the container ship Sh.

On the other hand, since the lower metal fitting 5 is at the position atwhich it overlaps the lower fitting portion 23, the lower metal fitting5 can be inserted into the upper corner fitting F through the engagingaperture Fa of the upper corner fitting F of the lower container Ctloaded earlier. At this moment, the lower fitting portion 23 is engagedwith the engaging aperture Fa of the upper corner fitting F.

After the upper container Ct has been lowered further and the lower faceof the main body portion 21 of the joint main body 2 has been placed onthe upper face of the upper corner fitting F of the lower container Ct,the upper container Ct descends by the height corresponding to theheight of the cutouts 4 x of the upper metal fitting 4. Since, duringthis, the lower corner fitting F abuts against the ascending/descendingmember 62 protruding upward from the main body portion 21 of the jointmain body 2 and bears the weight of the upper container Ct, theascending/descending member 62 is pressed down. Once theascending/descending member 62 has lowered, the articulated link 63 isstretched and its tip abuts against and thrusts out the engaged portion3 a. Therefore, the shaft 3 is rotated clockwise against the biasingforce of the torsion spring 34 and, inside the upper corner fitting F ofthe lower container Ct, causes the lower metal fitting 5 to rotate tothe position at which it is engaged with the engaging aperture Fa.Similarly, the upper metal fitting 4 is also rotated to the position atwhich it is further engaged with the engaging aperture Fa of the lowercorner fitting F of the upper container Ct. Then, finally, the lowerface of the lower corner fitting F of the upper container Ct is placedon the upper face of the main body portion 21 of the joint main body 2.At this moment, the balls 85 face the fitted recesses 3 x of the shaft 3since the fitted recesses 3 x of the shaft 3 that has been rotatedcommunicate with the openings of the inclined paths 2 x.

Consequently, the upper and the lower containers Ct are coupled throughthe container coupling metal joint 1 of which the upper metal fitting 4and the lower metal fitting 5 are respectively rotated to the respectivepositions at which each of them are respectively engaged with theengaging apertures Fa of the corner fittings F.

Under the status where the upper and the lower containers Ct are coupledthrough the container coupling metal joint 1, if the container ship Shrolls and is tilted by an angle exceeding a predetermined angle relativeto the horizontal plane, since, in the safety mechanism 8, one of theballs 85 rolls along the inclined paths 2× and it bridges the fittedrecess 3 x of the shaft 3 and the inclined path 2 x of the joint mainbody 2, the rotation of the shaft 3 can be prevented.

That is, even when the lower corner fitting F of the container Ct isreleased from the ascending/descending member 62 due to the tilting orthe jumping of the containers Ct caused by the rolling or pitching ofthe container ship Sh, the rotation of the shaft 3 is prevented by theball 85. Therefore, the shaft 3 can not be rotated by the biasing forceof the torsion spring 34 to the position at which the lower metalfitting 5 overlaps the lower fitting portion 23.

Consequently, the lower metal fitting 5, i.e., the container couplingmetal joint 1 can be prevented from being released from the engagingaperture Fa of the upper corner fitting F of the lower container Ct andthe coupled status of the upper and the lower containers Ct by thecontainer coupling metal joint 1 can be securely prevented from beingreleased.

On the other hand, when the container Ct is unloaded from the containership Sh, it is enough that the container Ct is lifted up through thecontainer crane Cr. That is, when the upper container Ct is lifted up,first, only the upper container Ct ascends by the height of the cutouts4 x of the upper metal fitting 4. During this, since the lower cornerfitting Fa of the upper container Ct is released from theascending/descending member 62, the shaft 3 is rotated counterclockwiseto the position at which the upper metal fitting 4 abuts against thestopper 24 by the biasing force of the torsion spring 34. At thismoment, since the lower metal fitting 5 is at the position at which itoverlaps the lower fitting portion 23, the lower metal fitting 5 canrelease the container coupling metal joint 1 from the upper cornerfitting F of the lower container Ct. Furthermore, since the lower metalfitting 5 thrusts back the tip of the articulated link 63 through theengaged portion 3 a of the shaft 3, it articulates the articulated link63 cooperating with the biasing force of the torsion spring and theascending/descending member 62 is thrust up.

In this way, the lower metal fitting 5 of the container coupling metaljoint 1 can be securely released from the upper corner fitting F of thelower container Ct by only lifting up the upper container Ct. Therefore,the operation of operation tools by workers or work at high places areunnecessary. In this case, the upper metal fitting 4 is at the positionat which it is engaged with the engaging aperture Fa of the lower cornerfitting F of the lifted container Ct. Therefore, the container couplingmetal joint 1 can not fall off from the lower corner fitting F of thecontainer Ct during the transfer of it from the container ship Sh to theapron Ap.

When the container Ct has been transferred to the apron Ap, once theoperation rod 241 is pressed down on the apron Ap, the shaft 3 isrotated counterclockwise by the biasing force of the torsion spring 34since the stopper 24 is retreated inside the joint main body 2, and theupper metal fitting 4 is rotated to the position at which it overlapsthe upper fitting portion 22. Therefore, the upper metal fitting 4together with the upper fitting portion 22, i.e., the container couplingmetal joint 1 can be released from the engaging aperture Fa of the lowercorner fitting F of the container Ct.

A third embodiment of the container coupling metal joint 1 is shown inFIGS. 17 to 19.

Similarly for describing the third embodiment of the container couplingmetal joint 1, the same reference numbers are given to the members sameas the members constituting the first embodiment of the containercoupling metal joint 1 described above. The detailed description forthose members is omitted and only the rotation mechanism 6 and thesafety mechanism 8 that differ from those of the first embodiment willbe described.

The rotation mechanism 6 of the container coupling metal joint 1comprises a guide path 21 d formed communicating with the cavity 2 ffrom upward to the cavity 2 f, in the main body portion 21 of the jointmain body 2 and a sliding member 64 slidably housed in the guide path 21d. The tip of the sliding member 64 is protruded into the cavity 2 fthrough the guide path 21 d and abuts against the engaged portion 3 a ofthe shaft 3. The upper end of the sliding member 64 is protruded beyondthe upper face of the main body portion 21 of the joint main body 2.

On the other hand, the safety mechanism 8 comprises a pair of fittedrecesses 2 y formed being spaced by 180 degrees to each other on theinner peripheral surface of the cavity 2 f of the joint main body 2, apair of declining inclined paths 3 y with their respective one endsopening to the outer peripheral surface of the shaft 3 being spaced by180 degrees, formed toward the center from the openings and balls 85 asrollers arranged capable of rolling freely in each inclined path 3 y. Itis arranged that each inclined path 3 y of the shaft 3 and each fittedrecess 2 y of the joint main body 2 are respectively in communicationwith each other when the shaft 3 is at a position where it has beenrotated by the sliding member 64 by a predetermined angle.

Next, the action of the third embodiment of the container coupling metaljoint 1 structured as described above will be described.

First, in the initial status, the upper metal fitting 4 is struckagainst by the stopper 24 and is at the position at which it is engagedwith the engaging aperture Fa of the lower corner fitting F of thecontainer Ct and, at this moment, the lower metal fitting 5 is at theposition at which it overlaps the lower fitting portion 23 of the jointmain body 2. The sliding member 64 abuts against the engaged portion 3 aof the shaft 3 and is thrust up along the guide path 21 d, and the tipof the sliding member 64 is protruded from the upper face of the mainbody portion 21 of the joint main body 2.

In order to attach the container coupling metal joint 1 to the engagingaperture Fa of the corner fitting F of the container Ct, first, thestopper 24 is caused to retreat inside the joint main body 2 by pressingdown the operation rod 241. During this, the shaft 3 is rotated to theposition at which the upper metal fitting 4 overlaps the upper fittingportion 22 by the biasing force of the torsion spring 34. Therefore, theoperation lever 71 is drawn backward through the control cable 72 by thedistance created by the rotation of the shaft 3, and is housed in thehousing portion 21 b of the joint main body 2 striking against the endof the depth of the housing portion 21 b. The engaged portion 3 a of theshaft 3 does not influence the sliding member 64 since it rotates whereit abuts against the tip of the sliding member 64.

Under this status, the upper metal fitting 4 is inserted into the lowercorner fitting F through the engaging aperture Fa of the lower cornerfitting F of the container Ct that is lifted up, by lifting up thecontainer coupling metal joint 1. Following this, once the operationlever 71 is drawn against the biasing force of the torsion spring 34,the shaft 3 is rotated clockwise and the upper metal fitting 4 isrotated to the position at which it is engaged with engaging aperture Fainside the lower corner fitting F. During this, the stopper 24 isprotruded from the upper face of the upper fitting portion 22 by thebiasing force of the spring, after this, the upper metal fitting 4 abutsagainst the stopper 24, is prevented from rotating counterclockwise anymore and is held at the position at which it is engaged with theengaging aperture Fa of the lower corner fitting F.

In this case, the lower metal fitting 5 is at the position at which itoverlaps the lower fitting portion 23. The container coupling metaljoint 1 descends due to its own weight and the cutouts 4 x of the uppermetal fitting 4 contact the inner peripheral surface of the engagingaperture Fa of the lower corner fitting F and are held there as well asthe upper fitting portion 22 is partially engaged with the engagingaperture Fa of the lower corner fitting F.

When the container coupling metal joint 1 has been attached as a resultof engagement of the upper metal fitting 4 with the engaging aperture Faof the lower corner fitting F of the container Ct, the container Ct islifted up using the container crane Cr and is loaded on the containership Sh. During this, since the upper metal fitting 4 is at the positionat which it is engaged with the engaging aperture Fa of the lower cornerfitting F of the container Ct being lifted up, the container couplingmetal joint 1 can not fall off from the lower corner fitting F of thecontainer Ct while the container Ct is transferred from the Apron to thedeck of the container ship Sh.

On the other hand, since the lower metal fitting 5 is at the position atwhich it overlaps the lower fitting portion 23, the lower metal fitting5 can be inserted into the upper corner fitting F through the engagingaperture Fa of the upper corner fitting F of the lower container Ctloaded earlier. At this moment, the lower fitting portion 23 is engagedwith the engaging aperture Fa of the upper corner fitting F.

After the upper container Ct has been lowered further and the lower faceof the main body portion 21 of the joint main body 2 has been placed onthe upper face of the upper corner fitting F of the lower container Ct,the upper container Ct descends by the height corresponding to theheight of the cutouts 4 x of the upper metal fitting 4. Since, duringthis, the lower corner fitting F abuts against the sliding member 64protruding upward from the main body portion 21 of the joint main body 2and bears the weight of the upper container Ct, the sliding member 64 isthrust and slid along the guide path 21 d. Once the sliding member 64has slid along the guide path 21 d, the tip of it abuts against theengaged portion 3 a of the shaft 3 and thrusts the engaged portion 3 aagainst the biasing force of the torsion spring 34. Therefore, the shaftis rotated clockwise and the lower metal fitting 5 is rotated to theposition at which it is engaged with the engaging aperture Fa.Similarly, the upper metal fitting 4 is also rotated to the position itis further engaged with the engaging aperture Fa of the lower cornerfitting F of the upper container Ct. Then, finally, the lower face ofthe lower corner fitting F of the upper container Ct is placed on theupper face of the main body portion 21 of the joint main body 2. At thismoment, the fitted recesses 2 y of the joint main body 2 are faced withthe balls 85 since each inclined path 3 y of the rotated shaft 3 and thefitted recess 2 y of the joint main body 2 communicates with each other(see FIG. 19).

Consequently, the upper and the lower containers Ct are coupled throughthe container coupling metal joint 1 of which the upper metal fitting 4and the lower metal fitting 5 are respectively rotated to the respectivepositions at which each of them are respectively engaged with theengaging apertures Fa of the corner fittings F.

Under the status where the upper and the lower containers Ct are coupledthrough the container coupling metal joint 1, if the container ship Shrolls and is tilted by an angle exceeding a predetermined angle relativeto the horizontal plane, since, in the safety mechanism 8, one of theballs 85 rolls along the inclined path 3 y and the ball 85 is positionedbridging the inclined path 3 y of the shaft 3 and the fitted recess 2 yof the joint main body 2, the shaft is prevented from rotating (see theposition shown by the dotted line in FIG. 19).

That is, even if the lower corner fitting F of the container Ct isreleased from the sliding member 64 due to the tilting or the jumping ofthe containers Ct caused by the rolling or pitching of the containership Sh, the shaft 3 is not rotated by the biasing force of the torsionspring 34 to the position at which the lower metal fitting 5 overlapsthe lower fitting portion 23 since the shaft 3 is prevented fromrotating by the ball 85.

Consequently, the coupled status of the upper and the lower containersCt by the container coupling metal joint 1 is securely prevented frombeing released by releasing of the lower metal fitting 5, i.e., thecontainer coupling metal joint 1 from the engaging aperture Fa of theupper corner fitting F of the lower container Ct.

On the other hand, when the container Ct is unloaded from the containership Sh, it is enough that the container Ct is lifted up through thecontainer crane Cr. That is, when the upper container Ct is lifted up,first, only the upper container Ct is lifted up by the height of thecutouts 4 x of the upper metal fitting 4. During this, the shaft 3 isrotated counterclockwise to the position at which the upper metalfitting 4 abuts against the stopper 24 by the biasing force of thetorsion spring 34 due to releasing off of the lower corner fitting Fa ofthe upper container Ct from the sliding member 64. At this moment, thecontainer coupling metal joint 1 can be released from the upper cornerfitting F of the lower container Ct since the lower metal fitting 5 isat the position at which it overlaps the lower fitting portion 23. Atthis moment, the sliding member 64 is thrust up along the guide path 21d since the tip of the sliding member 64 is thrust back through theengaged portion 3 a of the shaft 3.

In this way, the lower metal fitting 5 of the container coupling metaljoint 1 can be securely released from the upper corner fitting F of thelower container Ct by only lifting up the upper container Ct. Therefore,the operation of operation tools by workers or work at high places areunnecessary. In this case, the upper metal fitting 4 is at the positionat which it is engaged with the engaging aperture Fa of the lower cornerfitting F of the lifted container Ct. Therefore, the container couplingmetal joint 1 can not fall off from the lower corner fitting F of thecontainer Ct during the transfer of it from the container ship Sh to theapron Ap.

When the container Ct has been transferred to the apron Ap, once theoperation rod 241 is pressed down on the apron Ap, the shaft 3 isrotated counterclockwise by the biasing force of the torsion spring 34since the stopper 24 is retreated inside the joint main body 2, and theupper metal fitting 4 is rotated to the position at which it overlapsthe upper fitting portion 22. Therefore, the upper metal fitting 4together with the upper fitting portion 22, i.e., the container couplingmetal joint 1 can be released from the engaging aperture Fa of the lowercorner fitting F of the container Ct.

Furthermore, a fourth embodiment of the container coupling metal joint 1of the invention is shown in FIGS. 20 and 21.

Similarly for describing the fourth embodiment of the container couplingmetal joint 1, the same reference numbers are given to the members sameas the members constituting the first embodiment of the containercoupling metal joint 1 described above. The detailed description forthose members is omitted and only the rotation mechanism 6 and thesafety mechanism 8 that differ from those of the first embodiment willbe described.

The rotation mechanism 6 of the container coupling metal joint 1comprises an ascending/descending member 65 fitted capable ofascending/descending along the outer peripheral surface of the shaft 3,a spring 66 for urging the ascending/descending member 65 to its raisedposition and a spiral groove 3 z formed on the outer peripheral surfaceof the shaft 3. On the outer peripheral surface of theascending/descending member 65, a pair of operation portions 651 isextended outward each shifted by 180 degrees to each other and the tipsof the operation portions 651 are protruded beyond the upper face of themain body portion 21 of the joint main body 2. A pin 652 to be fitted inthe spiral groove 3 z of the shaft 3 is provided on theascending/descending member 65.

On the other hand, the safety mechanism 8 comprises a pair of inclinedpaths 2 x that are declining and formed extending in the direction ofthe diameter of the through hole 2 d and, of which one end opens to thecavity 2 f of the joint main body 2, a plurality of balls 85 as rollingelements arranged rollably on each inclined path 2 x and a pair offitted recesses 65 x formed being spaced by 180 degrees in theascending/descending member 65 corresponding to each opening of theinclined paths 2 x. It is arranged that each inclined path 2 x of thejoint main body 2 and each fitted recess 65 x of theascending/descending member 65 do not communicate with each other whenthe ascending/descending member 65 is at its raised position by thebiasing force of a spring 66 while each inclined path 2 x of the jointmain body 2 and each fitted recess 65 x of the ascending/descendingmember 65 communicate with each other when the ascending/descendingmember 65 is at its lowered position against the biasing force of thespring 66.

The inclined paths 2× and the fitted recesses 65 x are provided beingspaced by 180 degrees at respective positions shifted by a predeterminedangle such that they do not interfere with an operation portion 651.

The main body portion 21 of the joint main body 2 is provided with apressing member 67 capable of protruding and retreating and urged suchthat it protrudes from the upper face of the main body portion 21through a spring 68. When the pressing member 67 is at its raisedposition by the biasing force of the spring 68, balls 85 are housed inthe inclined paths 2× and, when the pressing member 67 is at its loweredposition against the biasing force of the spring 68, balls 85 arerespectively thrust out along each of the inclined paths 2× and it isarranged that the ball 85 running ahead at this moment is housed in thefitted recess 65 x of the ascending/descending member 65. In this case,the height of the protruding of the pressing member 67 from the upperface of the main body portion 21 of the joint main body 2 is set tobecome smaller than the height of the protruding of the operationportion 651 of the ascending/descending member 65.

Next, the action of the fourth embodiment of the container couplingmetal joint 1 structured as described above will be described.

First, at the initial status, the upper metal fitting 4 is caused toabut against the stopper 24 and is at the position at which it isengaged with the engaging aperture Fa of the lower corner fitting F ofthe container Ct. At this moment, the lower metal fitting 5 is at theposition at which it overlaps the lower fitting portion 23 of the jointmain body 2. The ascending/descending member 65 is at its raisedposition by the biasing force of the spring 66 and its operation portion651 is protruded upward from the upper face of the main body portion 21of the joint main body 2. Furthermore, the operation lever 71 is housedin the housing portion 21 b of the joint main body 2 remaining some roomto the end of the depth of the housing portion 21 b.

In order to attach the container coupling metal joint 1 to the engagingaperture Fa of the corner fitting F of the container Ct, first, thestopper 24 is caused to retreat inside the joint main body 2 from theposition at which it is protruded from the upper face of the upperfitting portion 22 by pressing down the operation rod 241 against thebiasing force of the spring. During this, the shaft 3 is rotated by thebiasing force of the torsion spring 34 to the position at which theupper metal fitting 4 overlaps the upper fitting portion 22. Thereby,the operation lever 7 is drawn backward through the control cable 72 bythe distance created by the rotation of the shaft 3, and is housed inthe housing portion 21 b of the joint main body 2 striking against theend of the depth of the housing portion 21 b. The spiral groove 3 z doesnot interfere with the pin 652 of the ascending/descending member 65 andthe ascending/descending member 65 is not raised due to the rotation ofthe shaft 3.

Under this status, the upper metal fitting 4 is inserted into the lowercorner fitting F through the engaging aperture Fa of the lower cornerfitting F of the container Ct that is lifted up, by lifting up thecontainer coupling metal joint 1. Following this, once the operationlever 71 is drawn, the shaft 3 is rotated clockwise and the upper metalfitting 4 is rotated to the position at which it is engaged with theengaging aperture Fa inside the lower corner fitting F. During this, thestopper 24 is protruded from the upper face of the upper fitting portion22 by the biasing force of the spring and, after this, the upper metalfitting 4 abuts against the stopper 24, is prevented from rotatingcounterclockwise any more and is held at the position at which it isengaged with the engaging aperture Fa of the lower corner fitting F. Therelation of positions of the spiral groove 3 z of the shaft 3 and theascending/descending member 65 is recovered as shown in FIG. 20 by theclockwise rotation of the shaft 3 by a predetermined angle.

In this case, the lower metal fitting 5 is at the position at which itoverlaps the lower fitting portion 23.

The container coupling metal joint 1 descends due to its own weight andthe cutouts 4 x of the upper metal fitting 4 contact the innerperipheral surface of the engaging aperture Fa of the lower cornerfitting F and are held there as well as the upper fitting portion 22 ispartially engaged with the engaging aperture Fa of the lower cornerfitting F.

When the container coupling metal joint 1 has been attached as a resultof engagement of the upper metal fitting 4 with the engaging aperture Faof the lower corner fitting F of the container Ct, the container Ct islifted up using the container crane Cr and is loaded on the containership Sh. Durng this, since the upper metal fitting 4 is at the positionat which it is engaged with the engaging aperture Fa of the lower cornerfitting F of the container Ct that is lifted up, the container couplingmetal joint 1 can not fall off from the lower corner fitting F of thecontainer Ct while the container Ct is transferred from the Apron to thedeck of the container ship Sh.

On the other hand, since the lower metal fitting 5 is at the position atwhich it overlaps the lower fitting portion 23, the lower metal fitting5 can be inserted into the upper corner fitting F through the engagingaperture Fa of the upper corner fitting F of the lower container Ctloaded earlier. At this moment, the lower fitting portion 23 is engagedwith the engaging aperture Fa of the upper corner fitting F.

After the upper container Ct has been lowered further and the lower faceof the main body portion 21 of the joint main body 2 has been placed onthe upper face of the upper corner fitting F of the lower container Ct,the upper container Ct descends by the height corresponding to theheight of the cutouts 4 x of the upper metal fitting 4. Since, duringthis, the lower corner fitting F abuts against the operation portion 651of the ascending/descending member 65 protruding upward from the mainbody portion 21 of the joint main body 2 and bears the weight of theupper container Ct, the ascending/descending member 65 is pressed downalong the shaft 3 through the operation portion 651. When theascending/descending member 65 is lowered against the biasing force ofthe spring 66, the pin 652 provided on the ascending/descending member65 is also lowered pressing downward the spiral groove 3 z of the shaft3. Therefore, the shaft 3 is rotated clockwise and, inside the uppercorner fitting F of the lower container Ct, causes the lower metalfitting 5 to rotate to the position at which it is engaged with theengaging aperture Fa. Similarly, the upper metal fitting 4 is alsorotated to the position at which it is further engaged with the engagingaperture Fa of the lower corner fitting F of the upper container Ct.Then, finally, the lower face of the lower corner fitting F of the uppercontainer Ct is placed on the upper face of the main body portion 21 ofthe joint main body 2.

On the other hand, while the container Ct is being lowered, the lowercorner fitting F abuts against the operation portion 651 of theascending/descending member 65 and starts to press down theascending/descending member 65 along the shaft 3, then, following this,the lower corner fitting F also abuts against the pressing member 67 andstarts to press down the pressing member 67 against the biasing force ofthe spring 68. Therefore, the balls 85 arranged in the inclined path 2 xare thrust up along the inclined path 2 x by the pressing member 67 andcauses the ball 85 ahead to be housed in the fitted recess 65 x of theascending/descending member 65 having already started to descend. Inthis case, the ball 0.85 is prevented from returning by the thrustingbody 67.

Consequently, the upper and the lower containers Ct are coupled throughthe container coupling metal joint 1 of which the upper metal fitting 4and the lower metal fitting are respectively rotated to the respectivepositions at which each of them are respectively engaged with theengaging apertures Fa of the corner fittings F.

The operation lever 71 is thrust out from and to the positionscorresponding respectively to the housing portion 21 b of the joint mainbody 2 and locking portion 21 a through the control cable 72 connectedto the shaft 3.

Under the status where the upper and the lower containers Ct are coupledthrough the container coupling metal joint 1, if the container ship Shrolls and is tilted by an angle exceeding a predetermined angle relativeto the horizontal plane, since, in the safety mechanism 8, one of theballs 85 rolls along the inclined path 2× and bridges the fitted recess65 x of the ascending/descending member 65 and the inclined path 2 xformed in the joint main body 2. Therefore, ascending of theascending/descending member 65 can be prevented.

That is, even when the lower corner fitting F of the container Ct isreleased from the operation portion 651 due to the shaking or thejumping of the containers Ct caused by the rolling or pitching of thecontainer ship Sh, as far as it is not released from the pressing member67, ascending of the ascending/descending member 65 can be preventedsince the ball 85 is housed in the fitted recess 65 x of theascending/descending member 65. At this moment, since clockwise rotationof the shaft 3 is caused by the ascending of the ascending/descendingmember 65, as far as the ascending of the ascending/descending member 65is prevented, the lower metal fitting 5 can not be rotated by thebiasing force of the torsion spring 34 to the position it overlaps thelower fitting portion 23.

Consequently, the lower metal fitting 5, i.e., the container couplingmetal joint 1 can be securely prevented from being released off from theupper corner fitting F of the lower container Ct. Therefore, the coupledstatus of the upper and the lower containers Ct by the containercoupling metal joint 1 is securely prevented from being released.

On the other hand, when the container Ct is unloaded from the containership Sh, it is enough that the container Ct is lifted up through thecontainer crane Cr. That is, when the upper container Ct is lifted up,first, only the upper container Ct ascends by the height of the cutouts4×of the upper metal fitting 4. During this, since the lower cornerfitting Fa of the upper container Ct starts to be releasedsimultaneously from the pressing member 67 and the operation portion651, first, the balls 85 roll along the inclined path 2× and get out ofthe fitted recess 65 x of the ascending/descending member 65 and,simultaneously, the ascending/descending member 65 is caused to ascendby the biasing force of the spring 66, then, the pin 652 of theascending/descending member 65 thrusts upward the spiral groove 3 z ofthe shaft 3. At the same time, the shaft 3 is rotated counterclockwiseby the biasing force of the torsion spring 34 to the position at whichthe upper metal fitting 4 abuts against the stopper 24. At this moment,the lower metal fitting 5 is at the position at which it overlaps thelower fitting portion 23. Therefore, the container coupling metal joint1 can be released from the upper corner fitting F of the lower containerCt.

In this way, the lower metal fitting 5 of the container coupling metaljoint 1 can be securely released from the upper corner fitting F of thelower container Ct by only lifting up the upper container Ct. Therefore,the operation of operation tools by workers or work at high places areunnecessary. In this case, the upper metal fitting 4 is at the positionat which it is engaged with the engaging aperture Fa of the lower cornerfitting F of the lifted container Ct. Therefore, the container couplingmetal joint 1 can not fall off from the lower corner fitting F of thecontainer Ct during the transfer of the container Ct from the containership Sh to the apron Ap.

When the container Ct has been transferred to the apron Ap, once theoperation rod 241 is pressed down on the apron Ap, the shaft 3 isrotated counterclockwise by the biasing force of the torsion spring 34since the stopper 24 is retreated inside the joint main body 2, and theupper metal fitting 4 is rotated to the position at which it overlapsthe upper fitting portion 22. Therefore, the upper metal fitting 4together with the upper fitting portion 22, i.e., the container couplingmetal joint 1 can be released from the engaging aperture Fa of the lowercorner fitting F of the container Ct.

In the fourth embodiment described above, a case where the spiral groove3 z is formed on the shaft 3 while the pin 652 is provided on theascending/descending member 65 and is fitted in the spiral groove 3 zhas been exemplified. However, a spiral groove may be formed on theinner peripheral surface of the ascending/descending member 65 while apin may be provided on the shaft 3 and may be fitted in the spiralgroove.

Furthermore, in the above-described embodiment, the inclined paths 2×and 3 y are not limited to the case where they are formed in thedirection of the diameter of the through hole 2 d or in the direction inwhich it is extended, i.e., formed being spaced by 180 degrees, and theangle of inclination against the direction from the front to the backcan be set optionally. Furthermore, the inclination of the inclinedpaths 2× and 3 y is not limited to five (5) degrees.

INDUSTRIAL APPLICABILITY

As described above, according to the container coupling metal joint ofthe invention, though it has a simple structure, when it is used, byonly stacking the container to be loaded, on the lower container, thecontainer coupling metal joint can couple the both containersautomatically and securely. Furthermore, the container coupling metaljoint can release the lower container automatically and securely by onlylifting up the upper container coupled to the lower container.Therefore, the operation of operation tools and work at high places areunnecessary and it is beneficial in terms of operation and safety.

1. A container coupling metal joint comprising: a joint main body havingan upper fitting portion and a lower fitting portion capable of fittinginto engaging apertures of corner fittings of containers; a shaftpivoted rotatably to the joint main body; an upper metal fitting and alower metal fitting connected integrally respectively to the upper endand the lower end of the shaft and capable of engaging with the engagingapertures of the corner fittings of the containers; and an operationmember for rotating the shaft, the joint main body being provided with arotation mechanism for rotating the shaft by receiving the action ofload of the container, the shaft being provided with a spring means forurging the upper metal fitting such that the upper metal fitting rotatesto the position at which it overlaps the upper fitting portion, theupper metal fitting having cutouts diagonally oppositely formed atcorner portions of its lower face on the side in engagement with theengaging apertures of the corner fittings of the containers, whereinwhen, through the operation member, the upper metal fitting is at theposition at which it comes into engagement with the engaging aperture ofthe corner fitting of the container, against the biasing force of thespring means, the lower metal fitting is at the position at which itoverlaps the lower fitting portion, wherein when the corner fitting ofthe container presses the rotation mechanism, the shaft is rotatedagainst the biasing force of the spring means, causing the lower metalfitting to rotate to the position at which it comes into engagement withthe engaging aperture of the corner fitting of the container, andwherein when the corner fitting of the container is raised along thecutout of the upper metal fitting and is released from the rotationmechanism, the shaft is rotated by the biasing force of the springmeans, causing the lower metal fitting to rotate to the position atwhich it overlaps the lower fitting portion.
 2. The container couplingmetal joint according to claim 1, wherein the rotation mechanism is apressing piece in the shape of substantially a right triangle fitted inslidably along a guide aperture and a guide groove formed on the jointmain body, and wherein the shaft is rotated by sliding of the pressingpiece pressed by the corner fitting of the container.
 3. The containercoupling metal joint according to claim 1, wherein the rotationmechanism includes an ascending/descending member capable of freelyascending and descending and an articulated link mechanism abutted bythe ascending/descending member and urged always in such a directionthat it is articulated, and wherein the shaft is rotated by stretchingof the articulated link mechanism through the ascending/descendingmember pressed by the corner fitting of the container.
 4. The containercoupling metal joint according to claim 1, wherein the rotationmechanism is a sliding member slidable along a guide path formed on thejoint main body, and wherein the shaft is rotated by sliding along theguide path of the sliding member pressed by the corner fitting of thecontainer.
 5. The container coupling metal joint according to claim 1,wherein the rotation mechanism includes an ascending/descending membercapable of freely ascending and descending along the outer peripheralsurface of the shaft and having an inwardly protruding pin, a spiralgroove formed on the shaft and into which is fitted the pin of theascending/descending member, and a spring urging theascending/descending member to its raised position, and wherein theshaft is rotated by descending of the ascending/descending memberpressed by the corner fitting of the container.
 6. The containercoupling metal joint according to claim 1, wherein the rotationmechanism includes an ascending/descending member capable of freelyascending and descending along the outer peripheral surface of the shaftand having a spiral groove formed on its inner peripheral surface, a pindisposed on the shaft and fitted into the spiral groove of theascending/descending member, and a spring urging theascending/descending member to its upper position, and wherein the shaftis rotated by descending of the ascending/descending member pressed bythe corner fitting of the container.
 7. The container coupling metaljoint according to claim 1, wherein the operation member includes anoperation lever and a connector with its one end connected to theoperation lever and with the other end connected to the shaft, andwherein the joint main body is formed with a locking portion capable oflocking the operation lever and a housing portion capable of housing theoperation lever.
 8. The container coupling metal joint according toclaim 1, wherein the upper fitting portion of the joint main body isprovided at its one corner portion a stopper urged in such a directionthat it protrudes from the upper face thereof and capable of freelyprotruding and retreating, the upper metal fitting being abutted againstthe stopper so that the upper metal fitting is held at a position atwhich it is engaged with the engaging aperture of the corner fitting ofthe container.
 9. The container coupling metal joint according to anyone of claims 1 to 8, wherein the joint main body is provided with asafety mechanism for preventing the rotation of the shaft by the biasingforce of the spring means when the container coupling metal joint istilted by a predetermined angle relative to the horizontal plane. 10.The container coupling metal joint according to claim 9, wherein thesafety mechanism includes a receptacle main body formed in the jointmain body, a lid body covering the upper opening of the receptacle mainbody, a moving element provided capable of freely moving back and forthwith respect to the receptacle main body, the moving element beingpenetrated by the connector and abutted by the operation lever, and arolling element capable of freely rolling and arranged on an outwarddeclined slope formed on the receptacle main body, and wherein when thesafety mechanism is tilted by an angle exceeding a predetermined angle,movement of the moving element is prevented by the rolling element. 11.The container coupling metal joint according to claim 9, wherein thesafety mechanism includes an inclined path declining outward formed onthe joint main body, a rolling element capable of freely rolling andarranged on the inclined path, and a fitted recess formed on the shaft,and wherein when the shaft is at the position at which it is rotatableby the articulated mechanism stretched, the inclined path of the jointmain body and the fitted recess of the shaft communicate with each otherand, under this status, in the case where the safety mechanism is tiltedby an angle exceeding a predetermined angle, rotation of the shaft beingprevented by fitting of the rolling element into the fitted recess. 12.The container coupling metal joint according to claim 9, wherein thesafety mechanism includes an inclined path climbing outward formed onthe shaft, a rolling element capable of freely rolling arranged on theinclined path, and a fitted recess formed on the joint main body, andwherein when the shaft is at the position at which it is rotatable bythe sliding member slid, the inclined path of the shaft and the fittedrecess of the joint main body communicate with each other and, underthis status, in the case where the safety mechanism is tilted by anangle exceeding a predetermined angle, rotation of the shaft beingprevented by fitting of the rolling element into the fitted recess. 13.A container coupling metal joint according to claim 9, wherein thesafety mechanism includes an inclined path declining outward formed onthe joint main body, a rolling element capable of rolling and arrangedon the inclined path, and a fitted recess formed on theascending/descending member, and wherein when the ascending/descendingmember is at its lowered position, the inclined path of the joint mainbody and the fitted recess of the ascending/descending membercommunicate with each other and, under this status, in the case wherethe safety mechanism is tilted by an angle exceeding a predeterminedangle, ascending of the ascending/descending member being prevented byfitting of the rolling element into the fitted recess.